INS and diabetes mellitus: Meta-regression (Table 1) showed that the pooled body weight reduction significantly interacted with the proportion of female participants (p = 0.016), the follow-up period (p = 0.018) and gastrointestinal side effect (p = 0.025), and had a borderline interaction with participants’ baseline age (p = 0.091) and the participants’ baseline HbA1c level (p = 0.077), but did not interact with baseline BMI level or body weight, insulin use, or the duration of diabetes.